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FFmpeg/libavdevice/v4l2enc.c
Anton Khirnov 08bebeb1be Revert "all: Don't set AVClass.item_name to its default value"
Some callers assume that item_name is always set, so this may be
considered an API break.

This reverts commit 0c6203c97a.
2024-01-20 10:34:48 +01:00

127 lines
3.8 KiB
C

/*
* Copyright (c) 2013 Clément Bœsch
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "libavutil/imgutils.h"
#include "libavutil/pixdesc.h"
#include "libavformat/avformat.h"
#include "libavformat/mux.h"
#include "v4l2-common.h"
typedef struct {
AVClass *class;
int fd;
} V4L2Context;
static av_cold int write_header(AVFormatContext *s1)
{
int res = 0, flags = O_RDWR;
struct v4l2_format fmt = {
.type = V4L2_BUF_TYPE_VIDEO_OUTPUT
};
V4L2Context *s = s1->priv_data;
AVCodecParameters *par;
uint32_t v4l2_pixfmt;
if (s1->flags & AVFMT_FLAG_NONBLOCK)
flags |= O_NONBLOCK;
s->fd = open(s1->url, flags);
if (s->fd < 0) {
res = AVERROR(errno);
av_log(s1, AV_LOG_ERROR, "Unable to open V4L2 device '%s'\n", s1->url);
return res;
}
if (s1->nb_streams != 1 ||
s1->streams[0]->codecpar->codec_type != AVMEDIA_TYPE_VIDEO) {
av_log(s1, AV_LOG_ERROR,
"V4L2 output device supports only a single raw video stream\n");
return AVERROR(EINVAL);
}
par = s1->streams[0]->codecpar;
if(par->codec_id == AV_CODEC_ID_RAWVIDEO) {
v4l2_pixfmt = ff_fmt_ff2v4l(par->format, AV_CODEC_ID_RAWVIDEO);
} else {
v4l2_pixfmt = ff_fmt_ff2v4l(AV_PIX_FMT_NONE, par->codec_id);
}
if (!v4l2_pixfmt) { // XXX: try to force them one by one?
av_log(s1, AV_LOG_ERROR, "Unknown V4L2 pixel format equivalent for %s\n",
av_get_pix_fmt_name(par->format));
return AVERROR(EINVAL);
}
if (ioctl(s->fd, VIDIOC_G_FMT, &fmt) < 0) {
res = AVERROR(errno);
av_log(s1, AV_LOG_ERROR, "ioctl(VIDIOC_G_FMT): %s\n", av_err2str(res));
return res;
}
fmt.fmt.pix.width = par->width;
fmt.fmt.pix.height = par->height;
fmt.fmt.pix.pixelformat = v4l2_pixfmt;
fmt.fmt.pix.sizeimage = av_image_get_buffer_size(par->format, par->width, par->height, 1);
if (ioctl(s->fd, VIDIOC_S_FMT, &fmt) < 0) {
res = AVERROR(errno);
av_log(s1, AV_LOG_ERROR, "ioctl(VIDIOC_S_FMT): %s\n", av_err2str(res));
return res;
}
return res;
}
static int write_packet(AVFormatContext *s1, AVPacket *pkt)
{
const V4L2Context *s = s1->priv_data;
if (write(s->fd, pkt->data, pkt->size) == -1)
return AVERROR(errno);
return 0;
}
static int write_trailer(AVFormatContext *s1)
{
const V4L2Context *s = s1->priv_data;
close(s->fd);
return 0;
}
static const AVClass v4l2_class = {
.class_name = "V4L2 outdev",
.item_name = av_default_item_name,
.version = LIBAVUTIL_VERSION_INT,
.category = AV_CLASS_CATEGORY_DEVICE_VIDEO_OUTPUT,
};
const FFOutputFormat ff_v4l2_muxer = {
.p.name = "video4linux2,v4l2",
.p.long_name = NULL_IF_CONFIG_SMALL("Video4Linux2 output device"),
.priv_data_size = sizeof(V4L2Context),
.p.audio_codec = AV_CODEC_ID_NONE,
.p.video_codec = AV_CODEC_ID_RAWVIDEO,
.write_header = write_header,
.write_packet = write_packet,
.write_trailer = write_trailer,
.p.flags = AVFMT_NOFILE,
.p.priv_class = &v4l2_class,
};